<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>弹性盒子模型</title>
    <style>
        div{
            height: 500px;
            width: 500px;
            background-color: darkgray;
            display: flex;
            flex-direction: row;
            justify-content:flex-end;
            align-items:flex-end;
        }
        .box1{
            height: 100px;
            width: 100px;
            background-color: red;
            /* flex: 7; */
           
        }
        .box2{
            height: 100px;
            width: 100px;
            background-color: green;
            /* flex: 1; */
        }
        .box3{
            height: 100px;
            width: 100px;
            background-color: blue;
             /* flex: 1; */
        }
    </style>
</head>
<body>
    <div>
        <div class="box1">

        </div>
        <div class="box2"></div>
        <div class="box3"></div>
    </div>
    
</body>
</html>